These are the main differences on the PE 175 X compared to PE 175 T (81-80)
Frame –six days bars instead of alloy bash plate, extra muffler mounting hole, little skid plates under vertical down tubes near foot pegs to stop those rails getting hooked up on logs etc because of no bash plate. Construction of steering head is welded together assembly that is much stronger that the one piece assembly previously used. Better steering stops.
Cylinder – exahaust port 1mm lower
Different head gasket = different compression ratio
Carburettor – jetting changes
CDI- different
Rear fender – larger tool bag platform
Front fender - I don’t know what difference is
Taillight – different shape and construction
Muffler bracket – different
Tank/side cover stickers – X has white Suzuki and 175 on top of 3 blue stripes
Thicker piston rings
Stronger piston
Exhaust pipe – better sound deadening material
Rims - stronger alloy, different nipple hole size
Spokes – thicker, stronger
Chain guide - T has 2 rollers, X has 1 roller and 1 nylon block, alloy plates also different.
Muffler - different
Air box boot hose clamps – different
Cylinder head rubbers.
there probably is a few more things im sure. Possibly different air box lid on Australian models (different size hole in lid) not 100% sure on that though.